<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>来抓我呀</title>
    <script>
        let arr = ["来抓我呀", "抓不到吧", "我又跑了", "气不气", "急不急"];
        let i = 1;
        function fn() {
            let btn = document.getElementById("btn");
            btn.style.left = Math.random() * 100 + "%";
            btn.style.top = Math.random() * 850 + "px";
            btn.value = arr[i++ % arr.length]
        }
    </script>
</head>
<body>
<!--
    当鼠标悬停在按钮上时,按钮会随机变换到浏览器屏幕的任意位置
    且按钮的内容发生改变
    依次变为:来抓我呀、抓不到吧、我又跑了、气不气、急不急
-->
<input id="btn" style="position:relative; left: 500px; top: 850px;" type="button" value="来抓我呀" onmouseover="fn()">

</body>
</html>